The manufacture of nonwoven fabrics for diverse applications has become a highly developed technology. Methods of manufacturing nonwoven fabrics include spunbonding, meltblowing, carding, airlaying, and so forth. It is not always possible, however, to produce by these methods a nonwoven fabric having all desired attributes for a given application. As a result, it is often necessary to treat nonwoven fabrics by various means to impart desired properties. For example, for medical applications such as surgeon's gowns, barrier properties to alcohol and blood penetration and bacteria are desired, and antistatic properties are important as well. Unfortunately, treatments for barrier properties using fluorocarbons, for example, and treatments for antistatic properties using salts are detrimental to each other which make it necessary to apply excessive amounts of one or both of the treatments. Current methods of treating nonwoven fabrics require slightly to moderately charged, either cationic or anionic, fluoropolymers suspended in water and then combined with anionic antistatic agents in a single bath treatment to produce an alcohol repellent, antistatic surgical fabric. Unfortunately, the antistatic agents currently being used are surface active in nature and negatively impact the water repellency of the finished web as measured by hydrostatic head testing. In addition, antistatic agents tend to destabilize suspensions of fluoropolymers of opposing ionic charge, leading to coagulation and filter plugging issues. Efforts to completely remove the antistat from the bath and apply it downstream on the body side of the web have resulted in a loss of alcohol repellency at equivalent fluoropolymer bath concentrations due to low adsorbed amounts of fluoropolymer on the fabric.
Accordingly, there is a need for a method of topically treating surgical fabric with an alcohol repellent chemistry that does not negatively effect, or at least minimizes the effect, on the water barrier of the fabric.